Pertinent Insights On OTC Orthoses And Orthotic Modifications

Prefabricated orthoses can provide improved support and other key benefits for patients with conditions such as plantar fasciitis. In addition to sharing their insights on OTC devices, these expert panelists provide pearls from their experience on common orthotic modifications that can have an impact.

Q:

Do OTC orthotics play a role in your practice? If so, how much and what do you look for in an OTC device?

A:

All three panelists use OTC devices. Ray Fritz, DPM, uses OTC arch supports at the time of the first visit if indicated. In addition to treatment for symptoms and immediate relief, patients often need additional support, according to Dr. Fritz. Lawrence Huppin, DPM, regularly uses prefabricated orthoses but notes that the most desirable features of a prefab device vary depending on the patient’s pathology. To treat common conditions like plantar fasciitis, metatarsalgia and first metatarsophalangeal joint complaints, Dr. Huppin says a prefab orthotic should have enough rigidity to resist deformation, a relatively close contour to the arch of the foot, a deep heel cup, a medial skive, a bit of forefoot valgus correction and a rearfoot post. He calls this a “functional prefab orthosis” and says it is the type of adult prefab device he uses most in his office. Similarly, Dr. Fritz uses OTC devices for those with plantar fasciitis and notes these devices help the patient realize the benefit of support. He adds that this helps his patients better appreciate the value of a custom orthotic, which may be the next treatment option. Dr. Fritz can also evaluate patient adherence and tolerance for a possible custom device based on the behavior of the patient while he or she wears an OTC device. Dr. Fritz uses four to five different brands that vary in length and bulk, and notes that some are better for different foot types. Contours, arch height, bulk and cost vary. His patients can try two or three different types, and he encourages them to select a device based on fit and comfort. His large office staff can assist in selecting devices and fitting the patient. Dr. Fritz cites the importance of having products readily available for patients along with appropriate assistance and instruction. As his patients do not have the time to get out and pick up recommended products, he cites the importance of starting fittings immediately. When it comes to children, Dr. Huppin says the most common condition he treats with prefabs is pediatric pes planus. In these cases, Dr. Huppin selects a device that has a deep heel cup, medial flange, medial skive and a rearfoot post. He often incorporates the same features into custom orthoses for pediatric flatfoot. Ronald Valmassy, DPM, calls OTC orthoses “extremely helpful” in potentially improving the patient’s gait or symptomatology. He typically uses an OTC support with additional forefoot or rearfoot varus or valgus posting, which he applies in the office.

Q:

What common orthotic modifications have you found to be the most effective?

A:

Both Drs. Valmassy and Fritz will use plantar fascia grooves. As Dr. Valmassy notes, a plantar fascial groove ranging from 2 to 6 mm in depth can be beneficial for patients who have symptomatology in the medial slip of the plantar fascial band. Dr. Fritz says another use for a groove for a tight plantar fascial band is for patients who say the orthotic is too hard and irritates the arch. As he explains, this is sometimes the case in the high arch foot type with inflammation along the central band of the plantar fascia. “Patients have come to my office with several sets of functional orthotics stating that they are too hard and they cause pain,” notes Dr. Fritz. “The easy way out is to make a composite device.” When prescribing the orthotic device, Dr. Valmassy chooses the material based on the patient’s weight, activity, shoes and foot function. He determines whether he wants to create an inversion force or an eversion force to the patient’s foot. In most instances, he notes functional foot orthoses attempt to decrease abnormal pronation with a combination of materials that have rigidity with increased rearfoot control. Typically, he will prescribe an inverted type of orthotic in the range of 5 to 15 degrees inverted, depending on the patient’s age and foot mechanics. Dr. Valmassy also usually makes a 2- to 6-mm Kirby modification to the medial heel cup. For patients with the most severe pediatric flatfoot, he will typically prescribe an orthotic device that is inverted by 10 degrees to 15 degrees via the Root technique with an additional 6 mm of Kirby skive. In contrast, if Dr. Valmassy wants to pronate or evert the foot to promote lateral stability, or decrease compression to the medial joint line of the knee, he typically has the laboratory introduce forefoot valgus correction into the cast. Usually, he will maximally pronate the foot in an attempt to create forefoot valgus and then prescribe a lateral Kirby skive of 2 to 6 mm with a higher lateral heel cup. In most instances, Dr. Valmassy will generally ask for a flat rearfoot post in both instances in order to create stability and gait. However, there are specific cases such as treatment of a retrocalcaneal exostosis in which Dr. Valmassy normally uses a 4-degree rearfoot post with 4 degrees of motion. As he advises, heel cup height should always be as deep as possible, depending on the type of shoe the patient wears. Dr. Valmassy emphasizes that an orthotic device will often exacerbate the initial symptomatology due to the contour of the medial portion of the heel cup and the amount of correction provided in an orthotic. For that reason, he advises applying a softer top cover to these devices or having a specific heel accommodation added to the device. When it comes to limb length and equality, Dr. Valmassy will add heel lifts to the rearfoot post when possible as normally up to ¼ inch can fit into most shoes. He uses a heel lift as a separate piece during the initial phases of treatment with an orthotic device, only after he is convinced that the patient can tolerate these specific heel lifts. Dr. Valmassy advises DPMs to always be aware of the fact that asymmetrical foot function will typically lead to some degree of functional limb length inequality. He adds that often controlling each foot independently with a properly designed orthotic device will eliminate the need for any additional lift. One might also want to consider tracing the plantar fascia with a non-permanent marker that will transfer into the negative cast, suggests Dr. Fritz. This marking transfers to the positive final mold that the technician uses to make the orthotic. He says the positive mold can be slightly built up along this marking and this will be reflected when the lab heats and presses the shell of the orthotic. Dr. Fritz notes that one can add viscoelastic polymer into the groove for extra protection. Dr. Fritz says one can also mark prominent metatarsal heads. He notes that these marked metatarsal heads as well as any marks for pads will be most specific and transfer from the foot to the positive mold and the final product. Dr. Fritz also suggests that DPMs mark sweet spots on any prominent area or difficult Charcot deformities. Exact molding of these areas in combination with any pad or gel additions can help create a comfortable orthotic, according to Dr. Fritz. Dr. Fritz is in private practice at Allentown Family Foot Care in Allentown, Pa. He is a Fellow of the American College of Foot and Ankle Surgeons. Dr. Huppin is the Medical Director for ProLab Orthotics/USA and is in private practice in Seattle. Dr. Valmassy is a Past Professor and Past Chairman of the Department of Podiatric Biomechanics at the California College of Podiatric Medicine. He is a staff podiatrist at the Center for Sports Medicine at St. Francis Memorial Hospital in San Francisco. Dr. Spencer is an Associate Professor of Orthopedics/Biomechanics at the Ohio College of Podiatric Medicine. He is also a Diplomate of the American Board of Orthopedics and Primary Podiatric Medicine. For related articles, see “How Current Orthotic Thinking Influences Orthotic Prescription” in the October 2010 issue of Podiatry Today or “Key Insights On Writing Orthotic Prescriptions” in the January 2006 issue.